Generally, acrylic acid is produced from oxidation of propylene which is a fossil resource. However methods of production which depend on fossil resources entail a risk of increasing atmospheric carbon dioxide. In addition, there is a risk that fossil resources will become depleted in the future.
In this regard, consideration has been given to the use of glycerin which is produced as a byproduct when producing biodiesel fuel from vegetable oils and fats or animal oils and fats, or when producing soap. In other words, consideration has been given to a method of producing acrylic acid by dehydrating and oxidizing glycerin produced as a byproduct.
There is no risk that glycerin produced from vegetable oils and fats will become a depleted resource due to its plant origin. Moreover since the carbon source is carbon dioxide in the atmosphere, there is the advantage of substantially not causing an increase in carbon dioxide in the atmosphere. Furthermore animal oils and fats are a resource which is created by the ingestion of feed such as vegetable oils and fats by livestock and therefore, the carbon source of that resource can also be treated as carbon dioxide in the atmosphere.
Known methods for producing acrylic acid from glycerin include a method for producing glycerin using a dehydration reaction and oxidation reaction of glycerin in the presence of molecular oxygen (for example, see Patent Literature 1). Furthermore in Patent Literature 2, a method of producing acrylic acid is disclosed in which glycerin is dehydrated in gaseous phase and the gaseous reactants produced by the dehydration reaction are reacted by gas-phase oxidation (for example, see Patent Literature 2). The glycerin used in these reactions normally has a high level of purity.    [Patent Literature 1] PCT International Patent Publication No. 06/114506    [Patent Literature 2] Japanese Unexamined Patent Application No. 2005-213225